U.S. patent number 10,271,621 [Application Number 13/411,892] was granted by the patent office on 2019-04-30 for gemstone with a chaton cut.
This patent grant is currently assigned to D. Swarovski KG. The grantee listed for this patent is Guenther Blasbichler, Karlheinz Eder, Maik Froehlich, Markus Sauer. Invention is credited to Guenther Blasbichler, Karlheinz Eder, Maik Froehlich, Markus Sauer.
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United States Patent |
10,271,621 |
Froehlich , et al. |
April 30, 2019 |
Gemstone with a chaton cut
Abstract
A gemstone with a chaton cut has tapering facets of a crown
adjoin a flat table all the way round inclined relative to the
table. The facets extend as far as a rondist at which the gemstone
has the largest transverse dimension. A pavilion of facets,
preferably terminating at a point, adjoins below the rondist. The
gemstone is at least partially made of glass, and the crown angle
(.alpha.) is between 40.5.degree. and 42.5.degree..
Inventors: |
Froehlich; Maik (Kundl,
AT), Eder; Karlheinz (Buch in Tirol, AT),
Blasbichler; Guenther (Innsbruck, AT), Sauer;
Markus (Mils, AT) |
Applicant: |
Name |
City |
State |
Country |
Type |
Froehlich; Maik
Eder; Karlheinz
Blasbichler; Guenther
Sauer; Markus |
Kundl
Buch in Tirol
Innsbruck
Mils |
N/A
N/A
N/A
N/A |
AT
AT
AT
AT |
|
|
Assignee: |
D. Swarovski KG (Wattens,
AT)
|
Family
ID: |
45833086 |
Appl.
No.: |
13/411,892 |
Filed: |
March 5, 2012 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20120227444 A1 |
Sep 13, 2012 |
|
Foreign Application Priority Data
|
|
|
|
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Mar 7, 2011 [AT] |
|
|
300/2011 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A44C
17/007 (20130101); A44C 17/001 (20130101) |
Current International
Class: |
A44C
17/00 (20060101) |
Field of
Search: |
;63/32 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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85102401 |
|
Jan 1987 |
|
CN |
|
1593285 |
|
Mar 2005 |
|
CN |
|
201153610 |
|
Nov 2008 |
|
CN |
|
101721021 |
|
Jun 2010 |
|
CN |
|
2 179 672 |
|
Apr 2010 |
|
EP |
|
2006/036937 |
|
Apr 2006 |
|
WO |
|
2010/035741 |
|
Apr 2010 |
|
WO |
|
Other References
Austrian Search Report dated Dec. 28, 2011 in Austrian Patent
Application No. A 300/2011. cited by applicant.
|
Primary Examiner: Lavinder; Jack W
Attorney, Agent or Firm: Stevens & Showalter, LLP
Claims
The invention claimed is:
1. An artificial gemstone with a chaton cut comprising: a crown
having a flat table and tapering facets, said tapering facets
adjoining said flat table all the way around said table and being
inclined relative to said table; said tapering facets of said crown
extending as far as a girdle of the gemstone at which the gemstone
has a largest transverse dimension, wherein said tapering facets of
said crown comprise a first set of crown facets each adjoining said
flat table with a tapered end of each of said first set of crown
facets and a second set of crown facets each adjoining said flat
table along a broad side of each of said second set of crown
facets; said first set of crown facets being inclined with respect
to a girdle plane at an angle between 40.5.degree. and
42.5.degree.; said second set of crown facets being inclined with
respect to said girdle plane at an angle between 33.5.degree. and
35.5.degree.; a pavilion of facets, each facet of said pavilion of
facets adjoining said girdle from below said girdle, said pavilion
of facets having only: a first set of pavilion facets each
extending from a point of said gemstone toward said girdle to
adjoin said girdle from below at a single point, wherein an angle
between said girdle plane and said first set of pavilion facets is
between 35.0.degree. and 37.0.degree., and a second set of pavilion
facets each adjoining said girdle along a broad side, wherein an
angle between said girdle plane and said second set of pavilion
facets is between 40.5.degree. and 41.0.degree.; and wherein said
artificial gemstone is made of glass.
2. The artificial gemstone according to claim 1, wherein said angle
of said first set of crown facets with respect to said girdle plane
is a crown angle and is between 41.75.degree. and
42.25.degree..
3. The artificial gemstone according to claim 2, wherein said crown
angle is 41.95.degree..
4. The artificial gemstone according to claim 3, wherein said angle
between said girdle plane and said second set of crown facets is
between 34.25.degree. and 34.75.degree..
5. The artificial gemstone according to claim 2, wherein said angle
between said girdle plane and said second set of crown facets is
between 34.25.degree. and 34.75.degree..
6. The artificial gemstone according to claim 1, wherein said angle
between said girdle plane and said second set of crown facets is
between 34.25.degree. and 34.75.degree..
7. The artificial gemstone according to claim 1, wherein said angle
between said girdle plane and said second set of crown facets is
34.52.degree..
8. The artificial gemstone according to claim 1, wherein said angle
between said girdle plane and said first set of pavilion facets is
between 36.0.degree. and 36.5.degree..
9. The artificial gemstone according to claim 1, wherein said angle
between said girdle plane and said first set of pavilion facets is
36.28.degree..
10. The artificial gemstone according to claim 1, wherein said
angle between said girdle plane and said second set of pavilion
facets is 40.73.degree..
11. The artificial gemstone according to claim 1, wherein said
first set of crown facets consists of six, eight, ten or twelve
facets.
12. The artificial gemstone according to claim 1, wherein said
second set of crown facets consists of six, eight, ten or twelve
facets.
13. The artificial gemstone according to claim 1, wherein said
first set of pavilion facets consists of six, eight, ten or twelve
facets.
14. The artificial gemstone according to claim 1, wherein said
second set of pavilion facets consists of six, eight, ten or twelve
facets.
15. The artificial gemstone according to claim 1, wherein: said
first set of pavilion facets extend between said girdle and said
point of said gemstone; and said second set of pavilion facets stop
short of said point of said gemstone.
16. The artificial gemstone according to claim 1, wherein said
single point at which each of said first set of pavilion facets
adjoins said girdle is aligned with a midline of said broad side of
a respective one of said crown facets in said first set of crown
facets.
17. The artificial gemstone according to claim 1, wherein said
second set of crown facets each adjoin said girdle with a tapered
end, said tapered end being aligned with a midline of said broad
side of a respective one of said facets in said second set of
pavilion facets.
18. An artificial gemstone with a chaton cut comprising: a crown
having a flat table and tapering facets, said tapering facets
adjoining said flat table all the way around said table and being
inclined relative to said table; said tapering facets of said crown
extending as far as a girdle of the gemstone at which the gemstone
has a largest transverse dimension, wherein said tapering facets of
said crown comprise a first set of crown facets each adjoining said
flat table with a tapered end of each of said first set of crown
facets and a second set of crown facets each adjoining said flat
table along a broad side of each of said second set of crown
facets; said first set of crown facets being inclined with respect
to a girdle plane at an angle between 40.5.degree. and
42.5.degree.; said second set of crown facets being inclined with
respect to said girdle plane at an angle between 33.5.degree. and
35.5.degree.; a pavilion of facets each adjoining said girdle from
below said girdle and having only: a first set of pavilion facets
each extending from a point of said gemstone to said girdle,
wherein an intersection between an edge of said girdle and each
facet in said first set of pavilion facets forms a single point and
an angle between said girdle plane and said first set of pavilion
facets is between 35.0.degree. and 37.0.degree., and a second set
of pavilion facets each adjoining said girdle along a broad side,
wherein an angle between said girdle plane and said second set of
pavilion facets is between 40.5.degree. and 41.0.degree.; and
wherein said artificial gemstone is made of glass.
19. An artificial gemstone with a chaton cut comprising: a crown
having a flat table and tapering facets, said tapering facets
adjoining said flat table all the way around said table and being
inclined relative to said table; said tapering facets of said crown
extending as far as a girdle of the gemstone at which the gemstone
has a largest transverse dimension, wherein said tapering facets of
said crown comprise a first set of crown facets each adjoining said
flat table with a tapered end of each of said first set of crown
facets and a second set of crown facets each adjoining said flat
table along a broad side of each of said second set of crown
facets; said first set of crown facets being inclined with respect
to a girdle plane at an angle between 40.5.degree. and
42.5.degree.; said second set of crown facets being inclined with
respect to said girdle plane at an angle between 33.5.degree. and
35.5.degree.; a pavilion of facets, each facet of said pavilion of
facets adjoining said girdle from below said girdle, said pavilion
of facets having only: a first set of pavilion facets each
extending from a point of said gemstone toward said girdle to
adjoin said girdle from below at a single point, wherein an angle
between said girdle plane and said first set of pavilion facets is
between 35.0.degree. and 37.0.degree.; and a second set of pavilion
facets each adjoining said girdle along a broad side, wherein an
angle between said girdle plane and said second set of pavilion
facets is between 40.5.degree. and 41.0.degree.; and wherein said
artificial gemstone is made of glass having a refractive index
between 1.50 and 1.60.
20. The artificial gemstone according to claim 19, wherein the
glass has a refractive index of 1.55.
Description
BACKGROUND OF THE INVENTION
(1) Field of the Invention
The invention relates to a gemstone with a chaton cut.
(2) State of the Art
In order to improve the brilliance and other optical properties of
a facetted cut gemstone, over the course of time many different
cuts have been developed that differ on the one hand by the number
of facets and on the other hand by the mutual geometrical
positional relationships of the facets.
In particular for the chaton sector the so-called oktant or xilion
cut (e.g. Swarovski stones A1200 and A1028) has in the past become
established in the market, since these cuts are considered to be
aesthetically pleasing and can be satisfactorily reproduced.
Important parameters for the evaluation of a gemstone are the
so-called "fire" and "light return", which is based on the numerous
internal light reflections. These light reflections are produced at
the individual facets, which are in special angular relationships
to one another characterizing the respective cut. The cut and the
material of a gemstone are thus decisive for the resultant fire and
light return.
The light return value specifies how much light from a predefined
solid angle range that is incident on the gemstone is directed back
to the observer in a relatively narrow (aperture angle 3.degree.)
solid angle range substantially along the axis of symmetry of the
stone.
A further important feature for evaluating the brilliance of a
gemstone is the fire. Fire denotes the property of a gemstone to
split the incident white light into its spectral components. The
expression of this property depends on the material (dispersion)
and also on the cut.
A gemstone with a chaton cut has a crown, also termed upper part,
with a defined number of side facets and a middle flat table, as
well as a pavilion, also termed lower part, with a defined number
of facets. The end of the gemstone remote from the table can be
formed as a point or as a rounded point in the form of a so-called
culet. A so-called rondist, also called a girdle, (circumferential
edge) can be arranged between the upper part and lower part. The
gemstone can be cut symmetrically or asymmetrically.
SUMMARY OF THE INVENTION
The object of the invention is to further improve the aesthetic
impression of a gemstone with a chaton cut by optimizing the
optical parameters, in particular the fire and light return.
This is achieved by a gemstone having the features of a chaton cut
in which tapering facets of a crown adjoin a flat table all the way
round inclined relative to the table. The facets extend as far as a
girdle at which the gemstone has the largest transverse dimension.
A pavilion of facets, which preferably terminate at a point,
adjoins below the girdle. The gemstone is made of glass and has a
crown angle (a) between 40.5.degree. and 42.5.degree.. Further, the
angle between the girdle plane and the crown facets that adjoin the
table by way of a broad side is between 33.5.degree. and
35.5.degree..
On account of the fact that the gemstone has a chaton cut, in which
the crown angle (.alpha.) is between 40.5.degree. and 42.5.degree.,
this surprisingly produces a particularly high light return with at
the same time a high fire. The scintillation (sparkling effect that
occurs on moving the gemstone) and the brilliance of the gemstone
are exhibited extremely effectively.
The crown angle is that angle which in a side view of the gemstone
is enclosed between the lateral boundary line of the crown and the
rondist or girdle plane, this boundary line being generated by an
orthogonal projection of a crown facet onto a plane containing the
longitudinal axis of the gemstone.
The rondist or girdle plane plane is that plane which is arranged
parallel to the table and in which the gemstone has the largest
cross-sectional dimension. The rondist plane is aligned
perpendicular to the longitudinal direction of the gemstone.
The light return and the fire can be measured, as is described
further hereinbelow for example with the aid of FIGS. 5 and 6.
Instead of an actual measurement the measurement can also be
computationally simulated on the basis of the geometry and material
of the gemstone.
Further advantageous modifications of the invention are defined in
the dependent claims.
It has been found that particularly preferred crown angle ranges
(.alpha.) lie between 41.75.degree. and 42.25.degree.. The crown
angle (.alpha.) is most particularly preferably 41.95.degree..
In a preferred embodiment of the invention the pavilion angle
(.beta.) is between 39.5.degree. and 41.5.degree., preferably
between 40.5.degree. and 41.0.degree. and most particularly
preferably is 40.73.degree..
The pavilion angle is that angle which in a side view of the
gemstone is enclosed between the lateral boundary line of the
pavilion and the rondist plane, this boundary line being generated
by an orthogonal projection of a pavilion facet onto a plane
containing the longitudinal axis of the gemstone.
Although the gemstone according to the invention may preferably be
made of a glass, a gemstone of natural or synthetic precious or
semi-precious stone or synthetic material with the chaton cut
according to the invention is also possible.
The crown of the gemstone, which is also known as the upper part,
has a table on which eight crown facets adjoin in each case via a
broad side. In one embodiment of the invention the angle between
these crown facets and the rondist plane is between 33.5.degree.
and 35.5.degree., (preferably between 34.25.degree. and
34.75.degree. and most particularly preferable is
34.52.degree.).
In addition the crown has eight further crown facets, which in each
case adjoin the rondist via a broad side. In one embodiment of the
invention the angle between these crown facets and the rondist
plane is between 40.5.degree. and 42.5.degree. (preferably between
41.75.degree. and 42.25.degree. and most particularly preferably is
41.95.degree.). The orthogonal projection of the last-mentioned
crown facets generates the crown angle.
The pavilion, also known as the lower part, has at least 16
pavilion facets, which terminate in the form of a point or a culet
on the end remote from the table. In this manner, in one embodiment
eight pavilion facets have a point that is arranged in the
direction of the rondist, while eight pavilion facets have a broad
side that is adjacent to the rondist. The end of this pavilion
facet remote from the broad side terminates in a point and is
directed away from the rondist. These pavilion facets adjoining the
rondist via the broad side have in one embodiment an angle between
39.5.degree. and 41.5.degree. relative to the rondist plane,
preferably between 40.5.degree. and 41.degree. and most
particularly preferably 40.73.degree.. The orthogonal projection of
the last-mentioned pavilion facets generates the pavilion
angle.
In one embodiment of the invention the angle between the rondist
plane and those pavilion facets that have a point adjoining the
rondist or that is arranged in the direction of the rondist, is
between 35.0.degree. and 37.0.degree. (preferably between
36.0.degree. and 36.5.degree., and most particularly preferably is
36.28.degree..
BRIEF DESCRIPTION OF THE DRAWINGS
Further details and advantages of the present invention are
described in more detail hereinafter with the aid of the
description of the figures and with reference to the drawings, in
which:
FIGS. 1a to 1c are respectively a side view, a plan view and a view
from below of a gemstone according to the invention,
FIG. 2 is a schematic representation of the definition of the crown
angle and pavilion angle,
FIGS. 3a and 3b compare respectively a gemstone of the prior art
(Swarovski A1200) and a gemstone according to the invention by
means of a schematic representation of ray paths,
FIG. 4 is a light return/fire diagram,
FIG. 5 is a schematic representation of the measurement arrangement
for measuring the light return,
FIG. 6 is a schematic representation of the measurement arrangement
for measuring the fire, and
FIGS. 7a to 7c show a further embodiment of a gemstone according to
the invention in a side view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1a shows a gemstone 1 according to the invention in a side
view. The rondist or girdle 4, which separates the crown 2, also
termed upper part, from the pavilion 3, also termed lower part, can
be recognized. The rondist 4 is that region of the largest
cross-sectional dimension of the gemstone 1. The symmetry axis
(longitudinal axis L) of the gemstone is also schematically
illustrated.
The pavilion 3 has two types of pavilion facets 8, 9 (two-layer
cut). In this case eight pavilion facets 9 have a broad side via
which they adjoin the rondist 4. The remaining pavilion facets 8
have a point that in each case adjoins the rondist 4.
The crown 2 also has 16 facets 10 and 11, as well as a flat table
5, which is aligned parallel to the rondist plane 7 and
perpendicular to the longitudinal axis L.
Eight crown facets 11 adjoin the rondist in each case via a broad
side and have a point that is aligned in the direction of the table
5. Eight further crown facets 10 adjoin the table 5 in each case
via a broad side (two-layer cut).
FIG. 1b shows a plan view of the crown 2 of the gemstone 1. The
symmetry of the gemstone 1 can be recognized by the schematically
illustrated coordinate cross on the table 5. The longitudinal axis
L runs through the center of the coordinate cross.
FIG. 1c shows a view from below the pavilion 3 of the gemstone 1. A
further coordinate cross to illustrate the symmetry of the gemstone
1 is symbolically shown at the point 6, which is formed by the
mutually adjoining pavilion facets 8.
FIG. 2 shows a schematic representation to illustrate the crown
angle .alpha., which is formed between the rondist plane 7 and the
lateral boundary line 16 of the crown 2, while the pavilion angle
.beta. is formed between the lateral boundary line 17 of the
pavilion 3 and the rondist plane 7.
FIG. 3a shows a gemstone 1' with a chaton cut of the prior art
(Swarovski A1200). The light rays 13 entering the gemstone are only
partially reflected back in the direction of view at the pavilion
3' on account of the angle with which the pavilion facets are cut,
in particular on account of the crown angle and the pavilion angle.
A proportion of the rays is refracted laterally or is scattered in
the form of the ray 15. The light return value is reduced.
FIG. 3b shows the same representation for a gemstone 1 according to
the invention. On account of the special geometrical arrangement of
the different facets and of the crown angle .alpha. and pavilion
angle .beta., the light return is significantly improved, since the
majority of the rays are totally reflected in the region of the
pavilion 3, so that virtually all the light rays 13 entering the
crown 2 are reflected back to the observer, after possibly
undergoing multiple reflection, in the form of light rays 15
leaving the crown 2.
The following table shows the differences of the known gemstone
A1200 of the applicant according to the prior art, compared to a
gemstone "I021" according to an embodiment of the invention.
FIG. 4 shows the position of this gemstone I021 according to the
invention in the so-called light return/fire diagram. It can be
seen that the gemstone according to the invention has
simultaneously high light return values and high fire values
compared to the prior art A1200 and A1028, which is another
gemstone of the applicant, and is thus superior to the prior art as
regards the optical properties and the aesthetic impression.
FIG. 5 shows in a schematic view a measurement arrangement for
measuring the light return of a gemstone. A gemstone 1 arranged in
a center of a base circle 17 of the hemisphere 16 is illuminated by
light rays 18 from a hemispherical illumination arrangement, so
that the crown 2 of the gemstone 1 is illuminated with white,
diffuse light, the light rays hemispherically striking the gemstone
1 and being reflected from the gemstone. The base circle 17 is
blacked out except for a recess for the gemstone 1, so that no
light is incident on the gemstone 1 from underneath the base circle
17. A region 19 of the hemisphere 16, which lies directly opposite
the gemstone 1 and has an aperture angle .alpha. of 46.degree., is
likewise blacked out. From this region too no light is incident on
the gemstone 1. The region 19 has a recess 20 with an aperture
angle .beta. of 3.degree.. This recess 20 serves as a narrow
measurement field for a detector. A detector measuring a stream of
light can thus be arranged above the recess 20.
Instead of this arrangement, the respective light-specific values,
such as for example the brightness in the region of this recess 20,
can be calculated in a computer simulation.
The amount of light reflected upwardly from the gemstone 1
represents a mean value over almost all possible illumination
arrangements and thus provides a quantitative measure for the light
return of the gemstone 1. The reflections take place at different
facets, so that light is reflected back to the recess directly on
first striking the gemstone, but also after multiple internal
reflections.
FIG. 6 shows a measurement arrangement for the fire value. The
gemstone 1 held by a holder 20 is illuminated through the opening
22 in the direction of its main axis with a directed beam from the
light source 21. The back-scattered light from the gemstone 1 is
recorded in color on a measurement field 24. The product values
from the saturation and illumination intensity of the light points
collected in the measurement field 25 are summed and thus give the
numerical value for the fire.
FIGS. 7a to 7c show in a schematic side view a gemstone according
to a further embodiment of the invention, similar to FIG. 1a,
though in this case the stone in contrast to the stone of FIG. 1a
has a pronounced circumferential edge 4a (rondist), which in plan
view encircles the gemstone.
The invention is obviously not restricted to the illustrated
embodiments, and in particular the number of facets can vary, in
contrast to the illustrated gemstone, which has in each case 8+
facets on both the table and pavilion, though other combinations of
facets can also be employed, for example 6+6, 10+10 or 12+12
facets. Odd numbers of facets are also possible. Also, the number
of facets between the crown on the one hand and pavilion on the
other hand do not have to match.
In the illustrated embodiment the crown as well as the pavilion
contains two different cutting angles (two-layer cut). In principle
single-layer and multiple layer gemstones are also possible.
Glass is used as preferred material, preferably with a refractive
index between 1.50 and 1.60, and most preferably 1.55. Other
materials, in particular natural stones, are however also feasible
and possible.
* * * * *